The technology pertaining to sound recording and reproduction originated late in the 19th century with several key inventions beginning with simple energy transforming devices and later including such devices as simple photographs, and development of the vacuum tube enabling electrical impulse amplification. Recent technology has incorporated the use of magnetic tape, digital data recording, and advanced digital signal processing. Such modern digital processing and recording techniques have more recently been integrated into a large segment of the music recording industry, enabling those skilled in the art, such as sound engineers or technicians using digital signal processing, to shape the final sound qualities of a signal source such as a musical instrument for example. Modern digital recording techniques typically also include the use of multiple signal sources and signal mixing consoles allowing the user to establish loudness levels of each signal in relationship to one another.
During the process of digital recording data is often compacted, reducing the data density to allow for more efficient transmission or storage, using a process known in the art as compression. Once the compressed data has been processed it must first be decompressed before the resulting sound can be heard. Data compression and decompression is achieved by applying certain algorithms which can be implemented in software applications or by a dedicated computer chip, or plurality thereof, known as a compressor/decompressor, commonly referred to in the art by its acronym: codec.
It is assumed by many users in the art that resulting sound, after compression and decompression, is generally not greatly affected by the process. However, depending on the type of signal source and compression/decompression techniques utilized, some adverse affects on data can occur during the process, sometimes causing modifications to the resulting sound. To ensure data integrity, every compression algorithm must have a matching decompression algorithm, and because compression reduces data density as previously described, a problem is presented in that the resulting sound is almost always invariably affected to some degree. Moreover, the degree to which the process of compression and decompression affects the resulting sound is a subjective judgment of the human ear. For example, a compression/decompression algorithm that creates only a small change to the resulting sound in terms of percent of total harmonic distortion, for instance, may cause the created sound, in its final form, to have undesirable audible characteristics when played back. In contrast, another algorithm having a high change percentage of total harmonic distortion may result in desirable audible effects resulting from, to a degree greater than that of the change to the data itself, the effects on the final sound.
To determine the effect of compression and decompression on a digital sound recording, a user in the current art must first make the recording and listen to the playback, making any changes as necessary including changing the mode of the codec, for example. By doing so, a user can judge what degree of effect the compression/decompression algorithm set currently in use has on the sound quality of the recording. A problem is presented by this method however, since during the recording process, a user wishing to listen to the digital recording must first stop recording and then go into a playback mode at which point the compression algorithm being used during recording is replaced with a decompression algorithm, thus allowing playback of recording. Such a method can require multiple, sometimes inconvenient and disruptive steps resulting in a cumbersome overall process for many users.
What is clearly needed is a method allowing a user, during the process of making a digital recording, to simultaneously monitor the sound being recorded, perceiving it as it would sound in its final form after compression and decompression. By utilizing such an improved method a user can eliminate many cumbersome steps in determining compression/decompression effects, thus making more efficient use of recording time and resources. Such a method is described in enabling detail below.